Production and investigation of mechanical properties of graphene/polystyrene nano composites

Working with pristine polystyrene is a great challenge due to its poor mechanical properties and is a massive task to utilize for packaging and structural applications. This study includes the analysis and optimization of tensile properties of graphene-polystyrene nanocomposites membrane to determine the reinforcing effect of nanofiller on tensile properties. The two-dimensional (2D) graphene sheets and samples of graphene-polystyrene nanocomposites were fabricated by liquid exfoliation and solution casting technique, respectively. Nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and thermogravimetric analysis (TGA) to evaluate their morphology, crystallographic phases, topography and thermal stability, respectively. Effect of filler concentration (0.06—0.74 wt. %), sonication time after mixing (3.18 – 36.82 min) and sonication temperature (16.48 – 58.52 ˚C) on ultimate tensile strength (UTS), percentage elongation and elastic modulus (E) were investigated and their responsive behavior was monitored respectively. In our experiment, it is shown that the concentration of graphene is a highly significant parameter. The optimized variables were found to be 0.60 wt. % of Graphene at 10 min of sonication time after mixing and 25 °C of sonication temperature. The obtained results demonstrate that the incorporation of graphene in the polystyrene matrix increases the mechanical properties of polystyrene. When compared with pristine polystyrene, the maximum increase witnessed in UTS, elongation and E was 97.36%, 82.70% and 174.08%, respectively

Diagnostic value of exome and whole genome sequencing in craniosynostosis.

BACKGROUND: Craniosynostosis, the premature fusion of one or more cranial sutures, occurs in ∼1 in 2250 births, either in isolation or as part of a syndrome. Mutations in at least 57 genes have been associated with craniosynostosis, but only a minority of these are included in routine laboratory genetic testing. METHODS: We used exome or whole genome sequencing to seek a genetic cause in a cohort of 40 subjects with craniosynostosis, selected by clinical or molecular geneticists as being high-priority cases, and in whom prior clinically driven genetic testing had been negative. RESULTS: We identified likely associated mutations in 15 patients (37.5%), involving 14 different genes. All genes were mutated in single families, except for IL11RA (two families). We classified the other positive diagnoses as follows: commonly mutated craniosynostosis genes with atypical presentation (EFNB1, TWIST1); other core craniosynostosis genes (CDC45, MSX2, ZIC1); genes for which mutations are only rarely associated with craniosynostosis (FBN1, HUWE1, KRAS, STAT3); and known disease genes for which a causal relationship with craniosynostosis is currently unknown (AHDC1, NTRK2). In two further families, likely novel disease genes are currently undergoing functional validation. In 5 of the 15 positive cases, the (previously unanticipated) molecular diagnosis had immediate, actionable consequences for either genetic or medical management (mutations in EFNB1, FBN1, KRAS, NTRK2, STAT3). CONCLUSIONS: This substantial genetic heterogeneity, and the multiple actionable mutations identified, emphasises the benefits of exome/whole genome sequencing to identify causal mutations in craniosynostosis cases for which routine clinical testing has yielded negative results

Diagnostic value of exome and whole genome sequencing in craniosynostosis

Background. Craniosynostosis, the premature fusion of one or more cranial sutures, occurs in ~1 in 2250 births, either in isolation or as part of a syndrome. Mutations in at least 57 genes have been associated with craniosynostosis, but only a minority of these are included in routine laboratory genetic testing. Methods. We utilised exome or whole genome sequencing to seek a genetic cause in a cohort of 40 subjects with craniosynostosis, selected by clinical or molecular geneticists as being high priority cases, and in whom prior clinically-driven genetic testing had been negative. Results. We identified likely associated mutations in 15 patients (37.5%), involving 14 different genes. All genes were mutated in single families, except for IL11RA (2 families). We classified the other positive diagnoses as follows: commonly mutated craniosynostosis genes with atypical presentation (EFNB1, TWIST1); other core craniosynostosis genes (CDC45, MSX2, ZIC1); genes for which mutations are only rarely associated with craniosynostosis (FBN1, HUWE1, KRAS, STAT3); and known disease genes for which a causal relationship with craniosynostosis is currently unknown (AHDC1, NTRK2). In two further families, likely novel disease genes are currently undergoing functional validation. In 5 of the 15 positive cases, the (previously unanticipated) molecular diagnosis had immediate, actionable consequences for either genetic or medical management (mutations in EFNB1, FBN1, KRAS, NTRK2, STAT3). Conclusions. This substantial genetic heterogeneity, and the multiple actionable mutations identified, emphasises the benefits of exome/whole genome sequencing to identify causal mutations in craniosynostosis cases for which routine clinical testing has yielded negative results